corrosion mechanisms in  stainless steel 

Metal loss uniform throughout the whole surface . Stainless steel with a pH level below one is more susceptible to corrosion attack 

GENERAL

02

CORROSION when crystallite borders are more prone to erode than interior surfaces, when the grain boundaries are depleted, known as grain boundary depletion, of the corrosion-inhibiting elements such as chromium by some mechanism.

INTERGRANULAR

Corrosion damage induced when two dissimlar materials are coupled in a corrosive electrolyte.  It occurs when two or more dissimilar metals are brought into electrical contact under water. 

galvanic